Voltameter for the electrolysis of water.



No. '7g4-,842...

PATENTBD APR. 7, 1903. P. GARUTI & B.. POMPIL'I. VOLTAMETEB. FOR THEELEGTROLYSIS 0F WATER.

APPLICATION FILED APR. 1].I 1902.

N0 MODEL.

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UNITED STATES PATENT OFFICE'.

POMPEO GARUTI AND RICCARDO IDOMPILLOF TIVOLI, ITALY.

VOLTAMETER FOR THE ELECTROLYSIS OF WATER.

SPECIFICATION formingpart of Letters Patent No. 724,842, dated April 7,1903.

| Application led April l'l, 1902. Serial-No. 102,490. (No model.) i

To all whom t may concer/'17.:

Be it known that we, POMPEO GARUTI, professor, and RICCARDOPoMPILLproprietor, of ll Via Vesta, Tivoli, near Rome, in the Kingdom ofItaly, have invented certain new and useful Improvements in Voltametersfor the Electrolysis of Water, of which the following is a speciication.

The invention has for its object a new and radical improvement. in ourvoltameters, United States Patent No. 629,070, datedJuly 18, 1899, forelectrolysis of water; and it consists, chieiiy, in a modified form ofthe metallic diaphragm used in connection therewith.

In order to understand clearly the invention, reference is had to theaccompanying drawings, in which y Figure l shows the diaphragm now inuse. Fig. 2 shows the improved diaphragm according to the presentinvention. Figs. 3 and 4. are vertical cross-sections on line X X ofFig. 2. Fig. 5 is a side View of an irnproved voltameter according tothe present invention. Fig. 6 is a cross vertical section online Y Y ofFig. 5.

In the electrolytic cells of the voltameters as originally patented ametallic diaphragm d was inserted between the two electrodes to preventthe mixing of the oxygen and of the hydrogen. Said diaphragm in order tofacilitate the passage of the ions ,from an electrode to another waspierced with small holes for a limited zone extending in longi-v tudinaldirection near its lower edge, as ap-A pears in Fig. l; but in order toavoid a mixing of the gases, which would render ineffective thediaphragm, the height of the said perforated zone must be a very smallone in comparison with the height of the electrode, as shown in Fig. l,and practically not much more than one inch and that of the electrodenot more than live inches. Because ofthe limited extension of theperforated Zone the diaphragm opposes a notable resistance to thepassage of the current and the transport of the ions, and .thiscircumstance necessitates the use of electrodes of little height andmaintains the intensity of the current under fourteen amperes per squarefoot of the electrodes. Of course a considerable number of cellsarranged in parallel was required for attaining a notable ei'iicency.The present inventionv has for its object the elimination of suchinconveniences by an improved/cons struction of diaphragm which willpermit the use oflarger electrodes without increasing theinternatresistance.

The improved diaphragm c according to :the present invention is shown inFig. 2.

Its central portion e, corresponding to the perforated zone of the olddiaphragms, is much wider than was formerly the case and can extendthroughout the whole electrode, except a little zone near the upper edgecorresponding to the gas-chamber; but from an excessive extension of theperforated zone would follow a mixing of the gases, and to prevent thiswe have found that it will `suffice to cover the perforated zone f,'Fig.3, with one,rtwo, or more metallic Webs d of thick texture, fastened onboth sides of the diaphragm, or instead of the perforated zone a largeropening e can be formed in the diaphragm, as shown in Fig. 4, and agreater number of metallic Webs applied, so as to cover the saidopening.

Obviously it is not altogether necessary to use metallic webs. They canalso be substituted by metallic fabrics or perforated Inetallic sheets,the invention consistingessen tially, in the application of a compounddiaphragm, which is obtained by disposing a certain number of simplelelementary'diaphragms the one against the other on both yfaces of theoriginal diaphragm.

The number of the elementary diaphragme employed will depend upon theirheight, or rather the height of the perforated zone covered by thediaphragme, because the greater the height of the perforated zone thegreater vmust be thenumber of the elementary diaphragms to insure aperfect separation of the gases. The elementarydiaphragmsplacedoneagainst the other are not electricallyinsulated from each other, andtherefore the whole diaphragm forms with regard to the current asingleinsulated body. Consequently the whole diaphragm remains neutral. Thediaphragm made of a plurality of webs prevents the gas -bubbles frompassing through the diaphragm, because such bubbles are kept by ICO theweb meshes. On further bubbles arriving they agglomerate and rise to thesurface withoutpassingthroughthediaphragm. The perforated Zone cantherefore be extended in height without any fear of its being traversedby the gases, and as such perforated zone has the weakest resistance tothe passage of the ions it follows that as such zone increases theelectrical resistance of the circuit diminishes.

Our system permits the use of higherlelectrodes having a larger activesurface, and, furthermore, the resistance being much diminished theyallow the use of a current havinga strength of more than thirty-sixamperes per square foot of the electrodes.

From the above description it will be seen that it is possible toconstruct very simple voltameters, consisting of a single cell, Figs. 5and 6, and of considerable power, capable of supporting a current offour hundred amperes and more. In these voltametersy the Walls g of thecells act as electrodes, and the central diaphragm c, which prevents themixing of the gases, is insulated by means of an insulating-packing Z,ofindia-rubber,asbestos, or the like, from the side walls of the cell.These several parts are maintained together by means of screw-bolts 7L,coated with a layer of india-rubber or the like. The gas escapes fromtwo little pipes fi fi, adapted on the upper walls of the cell.

The voltameter is made preferably of iron sheets, and the electrolyte isan alkaline solution of water.

A certain number of the cells above described, disposed the one againstthe other, as the books in the shelves of a library, form powerfulbatteries of voltameters, connected in series, acting as a singleapparatus, and by this arrangement high-tension currents can also beused.

We claiml. In a voltameter for the electrolysis of water, an aperturedmetallic diaphragm and pervious metallic coverings on both faces of theapertured portion of the diaphragm, as set forth.

2. In a voltameter for the electrolysis of water, an apertured metallicdiaphragm, and a plurality of foraminated metallic coverings on bothfaces of the apertured portion of the diaphragm, the said coverings oneach face being arranged close together and serving to diminish theinternal resistance of the voltameter, the said coverings alsopreventing the mixing of the gases, substantially as described.

3. A voltameter, comprisingahollow chamber provided withconducting-walls capable of serving as electrodes, an insulatedc0nducting diaphragm dividing said hollow chamber into insulatedcompartments and mutilated to allow communication between saidcompartments, and a plurality of metallic Webs disposed upon oppositesides of said diaphragm, for the' purpose of presenting largeconducting-surfaces.

4. A voltameter, comprising a hollow chamber provided withconducting-walls capable of serving as electrodes, an insulatedconducting-diaphragm dividing said chamber into insulated compartments,said diaphragm being provided with mutilations, and a plurality ot'elementary diaphragms disposed immediately adjacent to the maindiaphragm, so as to practically obstruct said mutilations.

5. A voltameter, comprisinga hollow chamber provided withconducting-walls capable of serving as electrodes, an insulatedconducting-diaphragm dividing said chamber into insulated compartments,said diaphragm being provided with mutilations and mounted centrallywithin said chamber, and a plurality of metallic webs arranged togetheras laminze and disposed upon opposite sides of said mutilations. l

6. A voltameter, comprising a hollow chamber with conducting-wallsacting as electrodes, an insulated conducting-diaphragm dividing saidchamber into insulated compartments, said diaphragm being provided withmutilations, and a plurality of metallic webs or thin perforatedmetallic sheets, said webs or sheets being disposed immediately adjacentto said diaphragm, so as to practically obstruct said mutilations whilepermitting the passage of the ions through the holes or the network.

7. Avoltameter,comprisingachamberhaving conducting-walls acting aselectrodes, an apertured diaphragm dividing said chamber into twocompartments insulated from each other and from the diaphragm, andpervious metallic coverings on both faces of the apertured portion ofthe diaphragm, as set forth.

POMPE() GARUTI. RICCARDO POMPILI. IVitnesses:

TRIG Ln'rTERIs LABOICETTA, T. I. URMEDETTI.

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